How about this for a quote from Windows guru and maven Paul Thurrot?
Unlike its immediate predecessors, IE 9 is not about more for more’s sake. Instead, IE 9 takes the same path Microsoft plowed with Windows 7 and then Windows Phone 7. It’s clean, simple and fast. It gets out of the way, letting web site content take center stage. It’s everything that IE has never been, then, and in addition to being the best browser that Microsoft’s ever made, it may very well be the best web browser on the market, even in this early public beta version. Maybe.
Internet Explorer 9 Beta (Paul Thurrot, SuperSite for Windows, 9/15/2010)
Wow! Talk about an incentive to tackle a Microsoft beta — something I’m rarely willing to do, outside of major OS and Service Pack releases. And because I’m working on a new thirteenth edition of my immortal classic HTML, XHTML, and CSS For Dummies and therefore also working with HTML 5 and CSS3, I am more than merely curious about how IE9 fares in the areas of support for such emerging Web standards. (FWIW, IE8 does OK with HTML 5, but is definitely way behind Google Chrome and Apple Safari in supporting CSS3).
I’m planning to dig into this environment over the next couple of weeks and will report on how IE9 does with HTML 5 and CSS 3 markup, particularly in areas where IE 8 proved deficient as we were working on our latest book. In the meantime, if you want to try it out for your own self — on a test machine or in a disposable VM, please — grab it and go from the IE 9 Beta Home Page.